The extracellular matrices of calcified tissues contain macromolecules which spatially and temporally regulate mineralization and osteogenesis. The long term objective of this project is to elucidate the regulatory properties of these macromolecules in terms of their structure and physical-chemical properties. Studies will be made of the disposition, reactivity and energetics of the electrostatic side chains in bone, dentine and skin matrices. Physical-chemical modification methods will be used.